Major basic science
discoveries in HIV
Dr. Matthew Marsden, Ph.D.
UCLA School of Medicine
A new disease…
On http://aids.gov/hiv-aids-basics/hiv-aids-101/aids-timeline/
A new disease…
•
By the end of 1981, there was a cumulative total of 270 reported cases of severe immune deficiency
among gay men, and 121 of those individuals had died.
•
In 1983, Luc Montagnier and Françoise Barré-Sinoussi reported the discovery of a new virus (later called
HIV) that is the cause of AIDS.
•
The first commercial blood test for HIV was licensed in 1985, allowing screening of the U.S. blood supply.
•
In 1987 the first anti-HIV drug (AZT) was approved by the U.S. Food and Drug Administration.
•
The first potent combination of anti-HIV drugs became available in 1995.
On http://aids.gov/hiv-aids-basics/hiv-aids-101/aids-timeline/
Some Significant Historical Discoveries in the field of Retrovirology
1908- Discovery of Retroviruses in chickens (Ellermann
and Bang).
1911- Cell free transmission of a sarcoma in chickens
(Rous) named “Rous sarcoma virus”.
Some Significant Historical Discoveries in the field of Retrovirology
1908- Discovery of Retroviruses in chickens (Ellermann
and Bang).
1911- Cell free transmission of a sarcoma in chickens
(Rous) named “Rous sarcoma virus”.
Many additional retroviruses were subsequently identified in
different animals, including important model systems:
1936- Mammary carcinoma in mice caused by milktransmitted, filterable agent (Bittner) termed “Mouse
Mammary Tumor virus”.
1957- Potent leukemia virus isolated from mice (Gross) named
“Gross murine leukemia virus”.
Some Significant Historical Discoveries in the field of Retrovirology
1908- Discovery of Retroviruses in chickens (Ellermann
and Bang).
1911- Cell free transmission of a sarcoma in chickens
(Rous) named “Rous sarcoma virus”.
Many additional retroviruses were subsequently identified in
different animals, including important model systems:
1936- Mammary carcinoma in mice caused by milktransmitted, filterable agent (Bittner) termed “Mouse
Mammary Tumor virus”.
1957- Potent leukemia virus isolated from mice (Gross) named
“Gross murine leukemia virus”.
1957- Visna, a neurological disease in sheep caused by a lentivirus was described, giving
rise to the concept of slow infections by these viruses (Latin: lentus, slow).
1980- 1st human retrovirus “Human T-cell leukemia virus 1” (HTLV-1) isolated.
For more information see “Retroviruses” textbook chapter here: http://www.ncbi.nlm.nih.gov/books/NBK19403/
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1970- Discovery of Reverse Transcriptase- Howard Temin and David Baltimore
(Received 1975 Nobel Prize in Physiology or Medicine)
“Central dogma” of molecular biology
http://www.ncbi.nlm.nih.gov/Class/MLACourse/Modules/MolBioReview/central_dogma.html
1970- Discovery of Reverse Transcriptase- Howard Temin and David Baltimore
(Received 1975 Nobel Prize in Physiology or Medicine)
“Central dogma” of molecular biology
However…..
Reverse
transcriptase
catalyzes
formation of
DNA using an
RNA template
http://www.ncbi.nlm.nih.gov/Class/MLACourse/Modules/MolBioReview/central_dogma.html
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1983- Identification of the HIV virus- Françoise Barré-Sinoussi and Luc Montagnier
(Shared 2008 Nobel Prize in Physiology or Medicine)
http://www.nobelprize.org/nobel_prizes/medicine/laureates/2008/press.html
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1987- First antiretroviral drug approved (AZT; azidothymidine; zidovudine)
Just 25 months from demonstrated efficacy in
vitro (in a test tube) to FDA approval- Record time
http://www.mcld.co.uk/hiv/?q=AZT
1987- First antiretroviral drug approved (AZT; azidothymidine; zidovudine)
The nucleoside analog reverse
transcriptase inhibitors (e.g. AZT) and
non-nucleoside reverse transcriptase
inhibitors (e.g. efavirenz) target this stage
of the virus life cycle.
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1989- Crystallization of protease enzyme
(allowed rational design of protease inhibitors)
1995- Protease inhibitors approved for clinical use
http://people.mbi.ucla.edu/yeates/153AH_2009_project/sriphanlop.html
http://physiologyonline.physiology.org/content
/26/4/236/F2.expansion.html
1989- Crystallization of protease enzyme
(allowed rational design of protease inhibitors)
1995- Protease inhibitors approved for clinical use
Protease inhibitors (e.g. Saquinavir)
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996- Discovery of the HIV coreceptors (CCR5 and CXCR4)
2007- Entry inhibitor approved based on this knowledge.
http://www.thefullwiki.org/Discovery_and_development_of_CCR5_receptor_antagonists
1996- Discovery of the HIV coreceptors (CCR5 and CXCR4)
2007- Entry inhibitor approved based on this knowledge.
Entry inhibitor (maraviroc)
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996: Discovery of protective effect of Δ32 CCR5 deletion
1997: Three-drug therapy (HAART) shown to delay progression
1997: Core structure of gp41 solved (6-helix bundle)
1997- Core structure of gp41 solved (6-helical bundle)
2003- Fusion inhibitor approved
http://www.pnas.org/content/98/20/11187/F1.expansion.html
1997- Core structure of gp41 solved (6-helical bundle)
2003- Fusion inhibitor approved
Fusion inhibitor (T-20, enfuvirtide)
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996: Discovery of protective effect of Δ32 CCR5 deletion
1997: Three-drug therapy (HAART) shown to delay progression
1997: Core structure of gp41 solved (6-helix bundle)
1997: Virus shown to persist in treated patients
HIV persistence during therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)
HIV persistence during therapy
Antiretroviral therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)
HIV persistence during therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)
HIV persistence during therapy
Antiretroviral therapy
•Latently infected CD4+ T lymphocytes are rare
in vivo:
•Approximately 1 per 106 total resting CD4+ T
cells
•Probably constitute around 105-106 cells per
patient
Approximately 1 per million resting CD4+ T cells harbor a latent provirus.
Rose Bowl Capacity = 92,542
Approximately 1 per million resting CD4+ T cells harbor a latent provirus.
Rose Bowl Capacity = 92,542
Like finding one person in 11 football stadiums.
To cure the infection we need to do this with 1,000,000
(one million) cells hidden in this way.
Activation/elimination strategy for clearing latently-infected cells:
Marsden and Zack (2010) Future Virol. 5(1): 97–109.
Prostratin is a phorbol ester isolated from the
Samoan medicinal plant Homalanthus nutans
(and previously from Pimelea prostrata)
Pimelea prostrata © 1991 Kennedy Harris
Homalanthus nutans (Mamala Tree)
http://members.ozemail.com.au/~pete
rrjones/plants/f.html
Traditionally used in treatment of jaundice and hepatitis
http://www.berkeley.edu/news/
media/releases/2004/09/29_sa
moa.shtml
U1 cell latency assay:
Add PKC agonist
Assay p24 concentration
in supernatant
2 days
Bugula neritina
Bryostatin 1:
•First isolated from Bugula neritina.
•Modulates PKC activity.
•Shows potential as an anti-cancer
therapeutic
•Has been shown to inhibit tumor invasion,
tumor growth in vitro and in vivo, and
angiogenesis.
http://www.marine.csiro.au
•In various phase 1 and phase 2 clinical
trials for treatment of cancer.
•Previously was very difficult to obtain and
hard to modify to alter activity.
Bryostatin 1
-Publication involves 7 bryostatin
analogs (bryologs).
-These can be synthesized for
several thousand dollars/gram
(rather than 1 million).
-Can be modified according to
need.
-Activate latent HIV expression
more efficiently in vitro (cell
lines).
J-Lat 10.6 latency assay:
Add latency activating agent
48 hours
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996: Discovery of protective effect of Δ32 CCR5 deletion
1997: Three-drug therapy (HAART) shown to delay progression
1997: Core structure of gp41 solved (6-helix bundle)
1997: Virus shown to persist in treated patients
1998: First non-nucleoside RT inhibitor approved
2003: Fusion inhibitor approved
2003: Restriction factors, TRIM5α and APOBEC3G, identified
2007: Integrase inhibitor approved
2007- Integrase inhibitor approved
Raltegravir
http://www.prn.org/index.php/management/article/integrase_inhibitors_raltegravir_elvitegravir_hiv_disease_478
2007- Integrase inhibitor approved
Integrase inhibitor (e.g. raltegravir)
Movie of the HIV Life Cycle
http://www.youtube.com/watch?v=9leO28ydyfU
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996: Discovery of protective effect of Δ32 CCR5 deletion
1997: Three-drug therapy (HAART) shown to delay progression
1997: Core structure of gp41 solved (6-helix bundle)
1997: Virus shown to persist in treated patients
1998: First non-nucleoside RT inhibitor approved
2003: Fusion inhibitor approved
2003: Restriction factors, TRIM5α and APOBEC3G, identified
2007: Integrase inhibitor approved
2007: Entry inhibitor approved (Maraviroc)
2008: Discovery of Tetherin
2008: Transplant of infected subject with Δ32 donor stem cells
http://www.nytimes.com/2011/11/29/health/new-hope-of-a-cure-for-hiv.html?pagewanted=all
HIV enters cells by binding to CD4 and a “corecepter” (often CCR5).
CCR5 is not functional in approximately 1% of Caucasians, which means they are highly
resistant (but not completely immune) to infection with most strains of HIV.
This mutation is called CCR532.
http://www.thefullwiki.org/Discovery_and_development_of_CCR5_receptor_antagonists
• The “Berlin Patient” was HIV positive and also developed leukemia.
• He underwent aggressive chemotherapy to clear the leukemia, and
in the process almost all the HIV+ cells in his body were also killed.
• This patient then received two bone marrow transplants from a
CCR5-32 individual.
• The new immune cells were not susceptible HIV, and the virus in
currently undetectable more than four years post-transplant.
Cells of the Immune System
Macrophage
Marrow
Mast cell
Eosinophil
Erythrocytes
Basophil
Monocyte
Bone
Megakaryocyte
Hematopoietic
stem cell
Multipotential
stem cell
Myeloid
progenitor Neutrophil
cell
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from : http://www.cancer.gov/cancertopics/understandingcancer/immunesystem
Cells of the Immune System
Macrophage
Marrow
Mast cell
Eosinophil
Erythrocytes
Basophil
Monocyte
Bone
Megakaryocyte
Hematopoietic
stem cell
Multipotential
stem cell
Myeloid
progenitor Neutrophil
cell
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from : http://www.cancer.gov/cancertopics/understandingcancer/immunesystem
Cells of the Immune System
Macrophage
Marrow
Mast cell
Eosinophil
Erythrocytes
Basophil
Monocyte
Bone
Megakaryocyte
Hematopoietic
stem cell
Multipotential
stem cell
Myeloid
progenitor Neutrophil
cell
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from : http://www.cancer.gov/cancertopics/understandingcancer/immunesystem
Cells of the Immune System
Macrophage
Marrow
Mast cell
Eosinophil
Erythrocytes
Basophil
Monocyte
Bone
Megakaryocyte
Hematopoietic
stem cell
Multipotential
stem cell
Myeloid
progenitor Neutrophil
cell
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from : http://www.cancer.gov/cancertopics/understandingcancer/immunesystem
Cells of the Immune System
Macrophage
Marrow
Mast cell
Eosinophil
Erythrocytes
Basophil
Monocyte
Bone
Megakaryocyte
Hematopoietic
stem cell
CCR5-32
Multipotential
stem cell
Myeloid
progenitor Neutrophil
cell
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from : http://www.cancer.gov/cancertopics/understandingcancer/immunesystem
Why can’t we use this approach for everybody?
• The chemotherapy and bone marrow transplant procedure was very
risky (the patient nearly died).
• Matching donors that are also CCR5-32 are very hard to find.
• The procedure is very expensive, time consuming, and requires
excellent medical facilities (not feasible in many parts of the world) .
• The patient will have to take immunosuppressive drugs for the rest
of their life to avoid problems with the transplant (this may be worse
than just taking the anti-HIV drugs).
Timeline of discoveries
1970s: Discovery of retroviruses and retroviral enzymes
1981: Epidemic first identified
1983: Identification of the HIV virus
1985: First commercial test to detect HIV
1987: First antiretroviral drug approved
1989: Crystallization of protease
1991: 2nd and 3rd anti-retrovirals approved
1995: Discovery of RANTES and MIP as suppressive factors
1995: Protease inhibitors approved
1996: Discovery of CXCR4 and CCR5 co-receptors
1996: Discovery of protective effect of Δ32 CCR5 deletion
1997: Three-drug therapy (HAART) shown to delay progression
1997: Core structure of gp41 solved (6-helix bundle)
1997: Virus shown to persist in treated patients
1998: First non-nucleoside RT inhibitor approved
2003: Fusion inhibitor approved
2003: Restriction factors, TRIM5α and APOBEC3G, identified
2007: Integrase inhibitor approved
2007: Entry inhibitor approved (Maraviroc)
2008: Discovery of Tetherin
2008: Transplant of infected subject with Δ32 donor stem cells
Thank you for your attention!
Questions?